Abstract The goal of this project is to build a state-of-the-science regional center of research excellence in Colombia, known as the Stanford-Colombia Collaboratory on Chronic Disease (S-C3), whose focus is on the prevention of major non-communicable diseases (NCDs) facing Colombia and the region, including cancer, diabetes, cardiovascular disease, and depression. Physical inactivity is one of the most important contributors to the global burden of NCDs, responsible for ~6-10% of major NCDs worldwide. The prevalence of physical inactivity and sedentary behavior is increasing in LMICs and approaching levels of higher income countries. In Colombia, 47% of adults and 74% of adolescents do not meet physical activity recommendations. Multi-level approaches that promote physical activity at the individual, family, community, and societal levels hold substantial promise for effectively preventing and controlling the major NCDs. We and others have demonstrated effective strategies for increasing physical activity across the socioeconomic gradient using approaches that leverage widely available information technologies such as smartphone applications (apps), SMS/text messaging, interactive voice response systems, and culturally tailored virtual advisors. This grant application builds upon an existing productive collaboration between scientists from Stanford University and the Universidad de los Andes in Bogot, Colombia. The S-C3 will enable scientists in the region to expand their expertise to include development and rigorous evaluation of behavioral interventions to promote physical activity that are effective and scalable. Our specific aims are the following: 1. Establish the necessary infrastructure to support a regional center of research excellence for NCD prevention in Colombia. The S-C3 will represent a partnership among key organizations in Colombia, including Universidad de los Andes, Universidad del Rosario, their partners from the sectors of Health, Sports and Recreation, as well as Transport and Urban Planning, and Stanford School of Medicine. 2. Build sustainable mechanisms for increasing research capacity aimed at developing and rigorously testing theory-based interventions that leverage culturally tailored, widely available technologies aimed at primary and secondary prevention of NCDs in Colombia. Capacity-building activities in Colombia will serve as a resource and a model for other Latin American countries. 3. Demonstrate the partnership's capability for engaging in cutting-edge behavioral intervention research to promote physical activity and prevent NCDs. We will conduct two initial pilot studies that target individual and community levels to increase physical activity in underserved populations. 4. Develop short-, mid-, and long-term trans-disciplinary research plans that focus on optimizing regional capacity for impactful change in the prevalence of NCD's in Colombia. We will leverage the partnership's expertise in creating effective physical activity interventions in diverse Latino populations.